How write a custom Heuristic, State dependent?

[Pietro-D]

I am trying to implement A* search to solve a planning problem based on industrial manufacturing. Additionally, I want to write a custom heuristic, but I am facing issues getting information from the current state, such as true facts.

[pellierd]

From the your planing problem you can obtain its initial state. Then, you can build a state using the class State. This class inherits from Bitset. It is then sufficient to iterate over the positive bits. To obtain the true fluent, simply retrieve the element from the problem's fluents array that is at the index of the true bit in the vector.

To implement a new heuristic in your case a suggest to inherit from StateHeuristic.

[Pietro-D]

@pellierd thanks for the answer. How can I associate bits in BitSector with true facts in the current state? I want to create a Map<String, Integer> where the key is the name of a true fact in the current state, and the value is its index in the BitSet. My goal is to identify only certain predicates that are true in the current state.